Tag Archives: Oak Ridge

Oak Ridge plant dismantling warheads at faster pace

May 30, 2006
OAK RIDGE (AP) — Workers at the Y-12 National Security Complex are dismantling nuclear warheads faster than ever before.
They’re trying to comply with arms-control agreements and reduce a backlog of old warheads.
Dan Linehan, a manager in the plant’s Directed Stockpile Work organization, says historically it’s been filler work. That’s changed this year.
The increase coincides with the construction of a $350 million storage center for bomb-grade uranium that is about half-finished.
There are also plans for a $1 billion Uranium Processing Facility that’s scheduled for completion around 2015.
Linehan says workers will still be dismantling warheads well beyond the time the facility is open.

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Cleanup, demolition slow for K-25 in Oak Ridge

ELIZABETH A. DAVIS, LEXINGTON HERALD
k25-oak-ridge.jpg
OAK RIDGE, Tenn. – The federal government spent 18 months building the massive K-25 uranium enrichment plant in this once-secret city for the World War II-era Manhattan Project.
Tearing it down has been much slower.
After the plant shut down in 1987, nearly 10 years passed before work began to decontaminate it and turn it and the other buildings on a sprawling 1,500-acre site into a private industrial park.
Another decade has gone by since then and the vacant K-25 building is in disrepair but still standing.
The Department of Energy cleanup project began in 1996, and a year later the site was renamed the East Tennessee Technology Park. Since then, it has faced several delays because of funding and safety issues.
Original estimates had the project costing $5 billion and taking generations to complete. But recent work on the technology park was split into two contracts that will together cost about $2 billion.
A completion date of September 2008 has been pushed back to summer of 2009. Buildings not occupied by the deadline could be torn down to save money on maintenance.
“It was very aggressive, very optimistic,” said Steve McCracken, DOE’s environmental manager, of the timeline. “For various reasons it will take longer and cost more. It’s just huge. We run into things every day.”
“If we have safety issues, we’re not going to push the schedule to our detriment,” he said.
K-25 is the name of the site’s centerpiece, a mile-long U-shaped building considered the largest in the world when it was built from 1943-45. It is also the name of the entire site that consists of many other buildings – known as K-33, K-31 and K-29, some built after the war.
K-25 enriched uranium in a process called gaseous diffusion. The uranium was fed into the nearby Y-12 plant to make highly enriched uranium that was used in the atomic bomb dropped on Hiroshima in 1945.
Many employees didn’t know the nature of their work until the bombing was announced on the radio.
During the Cold War, gaseous diffusion was the only process used to enrich uranium, and K-25 became a forerunner of other plants.
Farmland covering 59,000 acres was selected in 1942 to be one of the secret sites of the Manhattan Project. A city sprang up almost instantly and had 75,000 residents at its peak in 1945 working at K-25, Y-12 and the X-10 reactor.
Yellow radiation warning signs still dot the premises at K-25 but the armed guards at the entry gates are gone.
Currently, 25 companies are signed on as tenants in some of the old, refurbished buildings through leases negotiated by the Community Reuse Organization of East Tennessee.
“We’d always like to have many more clients visit and we’re working diligently to get there, but we have achieved some level of success we’re proud of,” CROET President Lawrence Young said.
CROET is in charge of finding tenants, negotiating the leases and sometimes maintaining buildings under lease.
The current tenants include a waste management company and an auto part component manufacturer. A motorsports race course has even been proposed.
Companies looking at the technology park have typical concerns about locating at a former uranium enrichment site with aging buildings. But Young says contamination shouldn’t be much of an issue.
“There’s reams of data that shows a worker is going to be safe in that environment just like they would be at any other industrial or business park, and by and large most companies accept that,” he said.
Still, two of the biggest buildings on the site – K-31 and K-33 – have been cleaned out and remain vacant. BRI Energy LLC of Florida announced tentative plans earlier in May to use K-31 for an ethanol production facility.
The buildings were grouped with K-29 in a $356 million cleanup contract awarded to BNFL Inc., now called BNG America. The company removed more than 156,000 tons of material and equipment from the buildings that together cover 4.8 million square feet of floor space. It was one of the largest decontamination and decommissioning projects in the country.
Officials later determined that the 650,000-square-foot K-29 needed to be torn down because it was not structurally sound, and Bechtel Jacobs started demolition earlier this year. Completion was targeted for July.
The buildings and others still vacant could come to the same fate as K-29 if leases cannot be signed in time.
“They are big buildings and as a result are expensive to maintain,” Young said.
“It just becomes a function of economics. If we can get tenants into those buildings that would ultimately allow us to maintain the buildings then obviously we would be fulfilling our mission and the buildings would be leased long term. Conversely if we’re not successful in doing that, then the department would have to make a decision with regard to the buildings.”
Officials say they will begin tearing down K-25 next April and finish in two years.
An enormous edifice from any angle, K-25 looks like an abandoned warehouse with peeling holes in the roof and exterior walls.
Cleaning up K-25 has been slow because of the age of the building and its lingering contamination. The roof was last repaired in 1994, and water has leaked in and onto the operating floor, making it “not safe to walk on or under,” said Jack Howard, manager of the three-building project.
“This is an example of one that sat too long,” McCracken said during a recent tour.
Now workers are draining and inspecting equipment and about 400 miles of piping inside the building. They use tiny cameras to check for residue.
The K-25 building cleanup was combined in a five-year Bechtel Jacobs contract worth $1.6 billion that also includes other parts of the Oak Ridge reservation.
Preservationists, who believe K-25 has historic significance, are hoping workers will leave a building footprint of the building or the north tower that forms the bottom of the U. The National Park Service is looking at creating a Manhattan Project park including several sites around the country including K-25.
McCracken moved to Oak Ridge with his family in 1947 when his father worked with the Atomic Energy Commission. He understands the concerns.
“I think Oak Ridge has a tremendous history that should be preserved,” he said.
“You can’t leave those big buildings with contaminants in them. What we have to do is save the legacy.”
As for the future, Young hopes the changes will draw more industry and not just tourists.
“Hopefully someone drives past who may not be from the area and they see it as simply a business industrial site,” he says, “and it’s not until they read the historic markers that they find that it was once the K-25 site.”

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'Extreme Engineering': Researchers use bacteria to reduce uranium to safe levels

HANNAH HICKEY
While the Cold War ended decades ago, its legacy will live for centuries in toxic waste. In remote corners of the country from Tennessee to the Pacific Northwest, dozens of federal laboratories struggle to clean up contaminants left from 50 years of weapons programs. New results show a promising technique for cleaning up uranium from some of the most severely contaminated areas by harnessing the powers of microbes already in the soil.
“Toxic uranium is often found in groundwater at places where uranium was either mined or enriched to make weapons,” said Craig Criddle, a professor of civil and environmental engineering at Stanford. “This uranium-contaminated water can migrate into surface waters, where it becomes a threat to organisms and water supplies. Excavation of contaminated soil or pumping and treating the water are prohibitively expensive and lead to additional disposal issues. An alternative is to stimulate naturally occurring subsurface microorganisms that can convert the dissolved uranium into a solid form that is not susceptible to transport by water.”
For the past six years, a research team at Stanford headed by Criddle has worked with a research team at the Oak Ridge National Laboratory (ORNL) in Tennessee headed by Phil Jardine, a soil chemist and distinguished research staff scientist there, to develop a possible solution to the problem. The group’s strategy took groundwater that originally contained more than 1,000 times the drinking-water regulatory limit for uranium and brought concentrations down to the limit. The technique and its early results are described in a pair of papers to appear June 15 in the journal Environmental Science and Technology, a publication of the American Chemical Society. The papers were published online on May 13.
Funding for the $4.6 million, six-year project was provided by the U.S. Department of Energy (DOE). The DOE Environmental Remediation Sciences Program (ERSP) supports basic research on bioremediation—the use of living organisms to clean up toxic waste—and aims to devise a safe, cost-effective solution to the problem of uranium contamination. It also oversees the Stanford-ORNL project and other field research projects at Oak Ridge and other locations. Until the early 1980s, the Oak Ridge laboratory enriched uranium for use in bombs. Wastewater was dumped in four unlined settling pits. When production ceased, lab officials drained the ponds, filled them with dirt and paved a parking lot the size of four football fields to cover the site.
That site is now home to an ERSP Field Research Center—the first DOE field test site for development of the science and technology needed to understand and predict long-term impacts of contamination and to mitigate those effects at 120 sites in 36 U.S. states and territories. The quantities are enormous: more than 475 billion gallons of contaminated groundwater; 75 million cubic meters of contaminated sediments; and 3 million cubic meters of leaking buried waste. The overarching DOE cleanup program has a budget of $220 billion and a timeline of more than 70 years to develop and implement solutions. This is the largest remediation effort of its type, and possibly the largest environmental cleanup ever attempted, Criddle said.
Among the most common contaminants at DOE sites are radioactive metals. These have spread over areas miles wide, making it impractical to store the dirt in closed containers or build barriers to separate the groundwater from drinking water. Uranium sticks to soil, making it impossible to remove efficiently by pumping contaminated groundwater to the surface and treating it there (where its removal creates another disposal problem). But uranium also doesn’t stick well enough to soil—over time, it dissolves into the water and can be transported in the groundwater to surface waters, where it is a threat to wildlife and water supplies. In humans, uranium causes kidney damage and cancer.
Extreme bioengineering
The extreme conditions at the field site called for a wide range of skills that could only be supplied by a large and diverse team. Members of the Stanford group are Criddle and Professors Peter Kitanidis and Scott Fendorf; senior research engineer Wei-Min Wu; consulting Professor Olaf Cirpka; postdoctoral researcher Jian Luo; administrative associate Julie Stevens; and doctoral students Mike Fienen, Margy Gentile, Matt Ginder-Vogel and Jennifer Nyman. Their partners at ORNL include Jardine and about one dozen other researchers and staff. The Stanford-ORNL team also worked with the consulting firm RETEC to design and construct the field system.
An important initial decision was where to work. The Stanford-ORNL team chose to set up camp less than 20 feet from the edge of the parking lot. They targeted groundwater 45 feet down because field measurements indicated that this water carried high levels of uranium from the ponds. But the uranium was not the only thing present in the water. They also discovered a witches’ brew of contaminants—the acidic mixture that was leftover from disposal of sulfuric, nitric and hydrochloric acids; toxic heavy metals; and solvents. Dealing with this mixture presented formidable technical challenges for the team but also was an opportunity to develop a strategy that could cut off contamination of the groundwater at its source.
The Stanford-ORNL team members developed a staged approach and employed an unusual amount of engineering to ensure process control, Criddle said. First, they prepared a region of the subsurface for microbial activity. This was accomplished by drilling wells and establishing a recirculation loop: Groundwater containing contaminants that would interfere with the uranium conversion was sucked to the surface, treated to remove those substances, then reinjected. The pH of the recirculating water was then increased from 3.6, roughly the acidity of vinegar, to 6, a level conducive to microbial growth.
After adjusting pH, the researchers provided weekly additions of ethanol to the recirculating water for more than a year. The ethanol stimulated growth of subterranean microbial populations that converted the uranium into an immobile form. After treatment, high levels of uranium remained on the soil, but the groundwater contained almost no uranium. Analysis of the soil-bound uranium confirmed that it was largely converted into the immobile form.

Bacteria are back

Bioremediation was used in the 1980s to clean up toxic organics, mainly spills of fuels and solvents. Bacteria basically ate the fuels—chomping down long-chain hydrocarbons—or they “breathed” the solvents and created nontoxic forms.
“Microorganisms also ‘breathe’ metals like uranium, converting it into a form that is immobile because it does not appreciably dissolve in water,” said Nyman, a doctoral student whose laboratory studies helped to guide operations in the field. After microbes convert the uranium, it’s “just sitting there, like a rock,” Criddle said. “In future studies, we hope to see how stable we can make that ‘rock.’ Ideally, it will remain in that form for thousands of years.”

[bhopal.net note: Oak Ridge, Tennessee, was left lethally contaminated by Union Carbide. The use of bacteria to “eat” radioactive contamination was pioneered by British Nuclear Fuels (BNFL) in the UK well over a decade ago. BNFL’s Chairman is Michael Parker, ex-CEO of Dow Chemical, which now owns Union Carbide]

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